Hi Ming:
I achieved this without consistency check. In FMOPER i maintained fund wise period assignment i-e for OPEX-JUL i maintained 01 against this fund in FMOPER and so on. This let me achieve my purpose. Now one can not simply select period 01 and put OPEX-MAY or any other fund than OPEX-JUL or CAPEX-JUL 
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Regards